This invention relates to a battery charging unit for an electrical device having a rechargeable battery, and in particular, to such a battery charging unit having a novel receptacle for receiving a contact foot of the electrical device that maintains proper electrical polarity between the charging unit and the contact foot and that retains the contact foot in the charging unit regardless of the orientation of the charging unit.
Portable electrical devices, such as flashlights and power tools, have come into great demand. Those devices often contain a rechargeable battery pack which is not readily removable from the device. Such a device usually has an external contact area which interfaces with a charging unit for charging or recharging the batteries in the device. In designing such devices and their corresponding charging units consideration must be given to assuring that the device is connected to the charging unit in a manner that assures proper electrical polarity between the contact area and the charging unit. Furthermore, since the designer cannot anticipate all of the different environments in which a charging unit may be installed, it is important that such a charging unit be able to retain the contact area of the device regardless of the orientation in which the charging unit may be mounted. Furthermore, in certain applications, such as those related to police and/or fire departments, the charging unit must be designed to withstand the rigors of such applications and yet be easy to use when time is of the essence. Heretofore, all of the foregoing design problems have not been adequately resolved in a single, known, charging unit.